Android: kill leftover webpagereplay servers.

Some bots downstream ended up with hundreds of instances.
Kill them all before start running the tests.

BUG=326540

Review URL: https://codereview.chromium.org/105733013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239479 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239479